How to make a text unreadable using CSS?

Imagine you are working on a page where you want to blur a text to make it unreadable for Anonymous users.

Please see the example below in the image:

This is achievable using CSS:

.class-name {

 text-shadow: 7px 7px 7px #0000;

 color: transparent;

}

That's it. All elements with class class-name will blur to become unreadable.